R2 Bucket MCP

list_files

List objects in an R2 bucket with optional prefix filter and pagination via continuation token.

Instructions

List objects in the R2 bucket. Optional prefix filters keys (e.g. vitalo/ or vitalo/2.1.0/). Combines with global R2_KEY_PREFIX if set. Use continuationToken to paginate.

Tool call template

This tool declares no required parameters. Add optional parameters from the input schema as needed.

{
  "id": 1,
  "jsonrpc": "2.0",
  "method": "tools/call",
  "params": {
    "arguments": {},
    "name": "list_files"
  }
}

Input Schema

Name	Required	Description
`prefix`	No	Key prefix filter (e.g. vitalo/ or vitalo/2.1.0/)
`maxKeys`	No	Max objects per page (default: 100, max: 1000)
`continuationToken`	No	Pagination token from a previous list_files response

Schema Changelog

Changes observed during successful MCP inspections.

First observedv1.0.0Jun 19, 2026

TDQS

A4.1/5.0

Behavior3/5

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

No annotations are provided, so the description must bear the burden. It describes the listing behavior and mentions combination with a global prefix, but it doesn't explicitly state that the operation is read-only or non-destructive, nor does it mention rate limits or authentication needs.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Conciseness5/5

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is two sentences, no fluff, front-loaded with the main action. Every clause earns its place, and it's easy to scan.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Completeness3/5

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

With no output schema, the description should explain the return format (e.g., keys, continuationToken). It does not. The parameter coverage is fine, but the missing return info is a gap for a listing tool.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Parameters4/5

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

The schema covers all three parameters with descriptions, achieving 100% coverage. However, the description adds value by explaining the combination with global R2_KEY_PREFIX and giving concrete prefix examples, which goes beyond the schema.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Purpose5/5

Does the description clearly state what the tool does and how it differs from similar tools?

The description clearly states the tool lists objects in an R2 bucket, with optional prefix filtering and pagination. It distinguishes from sibling tools (delete, get, upload) which perform different operations.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Usage Guidelines4/5

Does the description explain when to use this tool, when not to, or what alternatives exist?

The description provides clear usage context: listing objects, filtering by prefix, and paginating. It doesn't explicitly state when not to use it, but the sibling tools cover other operations, making the intent clear.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.

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